const koa = require("koa");
const app = new koa();
app.use(async ctx=>{
    let callbackName = ctx.query.callback || 'callback'
    // 返回jsonp
    var obj ={
        name:"xujiajia",
        age:20
    }
    ctx.body = callbackName + `(${JSON.stringify(obj)})`
    
})
app.listen(8090);